Adherent antimicrobial barrier and sanitizing agent

ABSTRACT

Provided are viscous and adherent food-safe antimicrobial compositions, and methods for using same in the immediate and residual decontamination of microbial-contaminated substrate surfaces, in reducing or precluding cutting implement-mediated transfer of surface contamination during cutting operations in the food industry, and for reducing or preventing transfer of contamination from contaminated surfaces in the food and pharmaceutical industries. Adherent antimicrobial protective layers are formed on substrate surfaces (e.g., processing equipment and utensils), providing a barrier (e.g., chemical and/or physical) to the passage or transport of microbial contamination between and among surfaces. The adherent formulations confer residual decontaminating activity, providing for prolonged killing of associated microbial contamination, are preferably formulated and applied as a gel, syrup or foam, and preferably comprise materials that are ‘generally-regarded-as-safe’ (GRAS) in food products, obviating post-treatment removal prior to consumption. Preferably, the inventive formulations are heated to a temperature ≧about 80° C. prior to application.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/584,105 filed 21 Aug. 2007 (to issue as U.S. Pat. No. 8,226,888 on 24Jul. 2012) and entitled “ADHERENT ANTIMICROBIAL BARRIER AND SANITIZINGAGENT,” which is the U.S. nationalization of PCT/US2004/043253 filed 22Dec. 2004 and entitled “ADHERENT ANTIMICROBIAL BARRIER AND SANITIZINGAGENT,” which claims the benefit of priority to U.S. ProvisionalApplication No. 60/531,321, filed 22 Dec. 2003 and entitled “ADHERENTKNIFE SANITIZER,” all of which are incorporated by reference herein intheir entirety.

FIELD OF THE INVENTION

The present invention relates generally to viscous, food-safeantimicrobial compositions and to methods for using same indecontaminating (e.g., immediate and residual) surfaces, and in formingan adherent protective layer on substrate surfaces (e.g., processingequipment and utensils) to provide a barrier to the passage of microbialcontamination between and among surfaces contacted by, or incommunication with a microbial-contaminated substrate surface.

BACKGROUND OF THE INVENTION

The presence of microbial contaminants that jeopardize product safety isa major problem in the food industry. Surface contamination of rawmaterials, product contact surfaces, and non-product contact surfacesare substantial challenges in the production of safe wholesome foods.Current sanitation practices involve preoperational cleaning andsanitation which does not confer residual sanitation properties to thesurfaces. A number of liquid sanitization agents have been developed andare used during processing, most of which run off and have short-termeffects.

An instructive example of issues relating to contaminated productsurfaces is the meat packing industry, which at times represents arelatively extreme case involving gross levels of contamination.Microbiological loads on external surfaces of cattle are, based onvarious art-recognized studies, one of the primary sources of bacterialcontamination of the derivative meat products. Therefore, loweringbacterial population densities on the surface of hides and carcass, andminimizing the transfer of contaminants could greatly reduce transfer ofsurface contamination (e.g., from contaminated hides) to the finalproduct.

Various precautions and treatments have been applied to reduce bacterialcontaminants on carcass surfaces; however, none can insure completedecimation of the microorganisms, or effectively preclude surfacetransfer of residual contamination. While decontamination interventionshave been designed for preventing, reducing, or eliminating microbialcontamination in the meat industry, the efforts have been focused onGood Manufacturing Practices and Sanitation Standard OperatingProcedures for controlling microbial contamination of equipment andutensils used in processing, and decontamination treatments forcontrolling microbial contamination on the meat surfaces. The exteriorsurface and internal organs of live animals sent to slaughter areregarded as the primary source for introducing microbial contaminationinto processing facilities.

The harvest phase of meat production is perhaps the most challengingfood production process in terms of controlling microbial contaminationand transfer thereof down the production line into final products. Theprocess of sanitary dressing of animals involves a number of steps inwhich implements used for the separation of hide from the carcass maybecome contaminated from the hide, and subsequently transfer thecontamination to other surfaces on or within the carcass. The transferof such contaminants is usually from microbial-contaminated hide to deepinside the carcass via cuts performed by hide-contaminated knives.

Currently, in the practice of ‘dehiding’ or general carcass fabrication,the cutting blade or other implements are decontaminated by dipping intohot water (>180° F.). When this step is done correctly, however, itensures only the cleanliness of the implements prior to use. Inpractice, the implements often touch contaminated surfaces (e.g., thehide) during the ‘dehiding’ process. Microbes on the hide are thusinadvertently transferred from the hide to the carcass by means of thecutting implement. Another mechanism of transfer is by workerscontacting the hide and subsequently touching another part of thecarcass. Additional means of contaminant transfer include direct contactbetween the contaminated surface of the hide and areas of the exposedcarcass, airborne transfer of contaminants, and contacts between productand non-product surfaces. Likewise, during the manufacturing of retailcuts, ‘primals’ and ‘subprimals’ are cut into smaller portions, andsurface contamination is transferred through implements and productcontact areas to the final product.

Contamination transfer issues also exist in the other segments of thefood industry. In fish processing, similar problems occur during thecleaning and filleting operations. In the production of ready-to-eatfood products, contamination travels from the raw processing areas tothe final production areas and to the products primarily because thesurfaces and the implements do not have residual antimicrobialcomponents on them to prevent/reduce contamination.

Therefore, there is a pronounced need in the art to devise antimicrobialintervention strategies that can act as a barrier to prevent thetransfer of bacterial contaminants from one surface to another duringthe preparation of foods, pharmaceuticals and other items which requireasepsis or low bio-burden.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B show a top view (A; left), and exposed surfaces (B;right) of meat cut using a blade dipped in water, or in EthidiumBromide-containing syrup formulated according to preferred aspects ofthe present invention. The results demonstrate the sacrificialprotective barrier aspect of the inventive adherent antimicrobialformulations with respect to the exemplary use of an implement (i.e., aknife) of a type typically used in meat processing facilities forcutting through portions of meat.

SUMMARY OF THE INVENTION

Aspects of the present invention provide antimicrobial solutions ormixtures in, for example, viscous gel, syrup or foam forms. Preferably,the inventive formulations comprise food-grade materials and can be useddirectly on foods and food product contact surfaces. In preferredaspects, the viscosity of the solution contributes to adherence andbarrier/sealant properties, while factors such as low or high pH,temperature, and/or active sanitizing molecules, act as decontaminants.The invention has utility in the application of barrier formulations toany appropriate surfaces encountered in, for example, the food orpharmaceutical product industry that contact or that may come intocontact with the products. The antimicrobial barrier is formulated as,for example, a gel, syrup or foam, to possess the desired physicalproperties by using a combination of ingredients as described hereinbelow. The specific formulation may vary depending on the type ofapplication.

Upon application, a layer of the formulation (e.g., in gel or syrupform) covers the surface/implement/product. This layer not onlysanitizes the surface, but also imparts residual effects for as long asthe layer is present. This action prevents any microbial contaminantscovered by the formulation from transfer to other surfaces, or tounderlying areas. The surface is covered with the formulation, andprolonged adherence of the solution to the implement provides residualdisinfecting properties. This is especially important if the surface inquestion is that of a knife used in food processing, where deep cuts mayresult in deposition of microbes in inaccessible layers. An equivalentfoam formulation will form a protective layer when sprayed onto thesurface of interest, and as such will eliminate the direct or indirecttransfer of contaminants. Additional uses of the inventive formulationsin the food industry include use in sanitizing implements that are usedto handle ready-to-eat products during last stages of processing, andgenerally use anywhere where residual antimicrobial property is desired.

In preferred forms, the invention comprises viscous formulations of, forexample gels, syrups or foams, which comprise‘generally-regarded-as-safe’ (GRAS) ingredients that possessantimicrobial properties. The antimicrobial aspect of the formulationcomprises, for example, acidic or basic compounds, chlorine oroxygen-based disinfectants, and with or without the addition ofalcohols. An example of an inventive product formulation includes use oflactic acid as disinfectant (e.g., at pH 1.5 to 2.0), and pectin as agelling/thickening agent.

Preferably, the inventive formulations comprise a GRAS agent for use infood products to confer the property of high viscosity. Preferredgelling/thickening agents include, but are not limited to: pectin,methylated pectin, gelatin, hydrosylated gelatin, agar, cornstarch,cross-linked starch, depolymerized starch, gelling vegetable proteinproduct, sodium alginate, carrageenan, and combinations thereof.

Preferably, the inventive formulations comprise a GRAS agent for use infood products that conveys antimicrobial properties. Preferred agentsinclude, but are not limited to: organic acids such as acetic, citric,and lactic acid; acidified calcium sulfate; acidified sodium chlorite;peracetic acid and other peroxyacetic acids and/or mixtures;percarbonates, ammonium hydroxide, quaternary ammonium salts,cetylpyridinium chloride, polyphosphates, glycolic acid, sodiummetasilicate, trisodium phosphate, enzymes such as lysozyme, protease,lipase and phospholipase, alcohols such as ethanol and isopropoanol, andcombinations thereof.

Preferably, when used as a foam application the invention incorporates aGRAS agent for use in food products which conveys emulsifying and foamstabilization properties. The following agents are preferred but are notlimited to: calcium lactate, lecithin, and glycerol.

Preferably, when used as a foam application, the invention incorporatesa GRAS agent for use in food products that conveys surfactantproperties. Preferred agents include, but are not limited to: sodiumlauryl sulfate, Tween 20, 40, 60, and 80, and combinations thereof.

Specific aspects provide a method of reducing or preventing transfer ofcontamination from a contaminated surface; comprising coating acontaminated surface or a portion thereof with an adherent antimicrobialbarrier composition, comprising: from about 0.1 to about 25% (wt) of agelling or thickening agent; from about 0.1 to about 10% (wt) of anemulsifier or stabilizer; from about 0.05 to about 10% (wt) of asurfactant; and an antimicrobial agent, whereby transfer ofcontamination from the surface is reduced or precluded. Preferably, theadherent antimicrobial barrier composition further comprises from about0.1 to about 15% (wt), or about 1 to about 5% (wt), of one or more C₁₋₁₀alcohols. Preferably, the adherent antimicrobial barrier composition isheated to at least 80° C. prior to application.

Additional aspects provide a method of reducing or precluding transferof surface contamination during cutting operations, comprising: coating,prior to cutting through a target surface, at least one of: a cuttingimplement or a portion thereof; and the target surface or a portionthereof with an adherent sacrificial composition layer, wherein thesacrificial layer is partially transferable between the cuttingimplement and the target surface during cutting, whereby a protectivelayer is provided to the cutting implement surface while cutting throughthe target surface. Preferably, the adherent sacrificial compositioncomprises at least one agent selected from the group consisting of: fromabout 0.1 to about 25% (wt) of a gelling or thickening agent; from about0.1 to about 10% (wt) of an emulsifier or stabilizer; from about 0.05 toabout 10% (wt) of a surfactant; and an antimicrobial agent. Preferably,the adherent sacrificial composition further comprises from about 0.1 toabout 15% (wt), or about 1 to about 5% (wt), of one or more C₁₋₁₀alcohols. Preferably, the adherent sacrificial composition is heated toat least 80° C. prior to application.

Further aspects provide an antimicrobial barrier composition,comprising: from about 0.1 to about 25% (wt) of a gelling or thickeningagent; from about 0.1 to about 10% (wt) of an emulsifier or stabilizer;from about 0.05 to about 10% (wt) of a surfactant; and an antimicrobialagent. Preferably, the antimicrobial barrier composition furthercomprises from about 0.1 to about 15% (wt), or about 1 to about 5% (wt),of one or more C₁₋₁₀ alcohols. Preferably, the gelling or thickeningagent is present in an amount selected from the group consisting of fromabout 0.1 to about 4% (wt), from about 5 to about 15% (wt), and about2.5% (wt), and is selected from the group consisting of pectin,methylated pectin, gelatin, hydrosylated gelatin, agar, cornstarch,cross-linked starch, depolymerized starch, gelling vegetable proteinproduct, sodium alginate, carrageenan, and combinations thereof.Preferably, the emulsifier or stabilizer is present in an amountselected from the group consisting of from about 0.1 to about 1% (wt),from about 1 to about 5% (wt), and about 0.2% (wt), and is selected fromthe group consisting of calcium lactate, lecithin, glycerol, andcombinations thereof. Preferably, the surfactant is present in an amountselected from the group consisting of from about 0.05 to about 0.5%(wt), from about 1 to about 5% (wt), and about 0.2% (wt), and isselected from the group consisting of sodium lauryl sulfate, Tween 20,40, 60, and 80, and combinations thereof. Preferably, the antimicrobialagent is at least one of an acidic agent and a basic agent, present inan amount selected from the group consisting of from about 0.1 to about15% (wt), from about 1 to about 5% (wt), and about 2% (wt), suitable toimpart a pH of less than about 3, or greater than about 10, and isselected from the group consisting of acetic acid, citric acid, andlactic acid, acidified calcium sulfate, acidified sodium chlorite,peracetic acids, percarbonates, ammonium hydroxide, quaternary ammoniumsalts, cetylpyridinium chloride, polyphosphates, glycolic acid, sodiummetasilicate, trisodium phosphate, and combinations thereof. Preferably,the antimicrobial agent is selected from the group consisting ofproteases, lipases and phospholipases, alcohols, and combinationsthereof. Preferably, the antimicrobial agent is heat. Preferably, theantimicrobial barrier composition is provided as a formulation selectedfrom the group consisting of semi-solids, gels, liquids, syrups,aerosolized formulations, foams, colloidal suspensions, and combinationsthereof.

DETAILED DESCRIPTION OF THE INVENTION

Antimicrobial barrier formulations are provided that, by virtue ofadherent properties, have utility to seal off microbial contaminants,and eliminate contaminant transfer to other surfaces. The inventiveformulations also confer residual antimicrobial property to surfaces(e.g., foods, equipment, production areas), and impart antimicrobialproperties to surfaces to which they are applied. In particular aspects,the technology comprises an antimicrobial barrier that can translocateduring use of formulation-coated implement and thus confer contaminanttransfer protection to implements which are used in processing. Theinventive formulations can also be applied to contaminated surfaces,such as hide, to cover the surface and exclude and disinfectcontaminants. The inventive subject matter not only has utility forcovering of utensils and equipment in the plant, but also in coveringany surface where microbial contamination may be established and presenta risk, the surfaces including, but not limited to post-mortem animalsurfaces, plant floors, walls, conveyor belts, etc. Antimicrobialproperties, for purposes of the present invention, are conferred bychemical (sanitizing agents) or physical (pH, oxidation, temperature)means.

In preferred embodiments, the invention provides formulations for use infood production areas as a direct or indirect antimicrobial barrierapplied to food surfaces, or to food or pharmaceutical productionsurfaces, and which confers protection to the food or drugs beingprocessed.

Accordingly, preferred aspects of the present invention provide anadherent liquid (low to high viscosity), gel, or foam formulation,comprising: (i) a food-grade gelling or thickening agent (e.g.,preferably a GRAS compound approved as a direct food additive or foodcontact ingredient that will not affect the food and will have noadverse effect on humans upon ingestion; (ii) a food-grade emulsifyingor foam stabilization agent (e.g., preferably a GRAS compound asdescribed above); (iii) a food-grade surfactant (e.g., preferably a GRAScompound as described above); and, (iv) a food-grade acidic or basicagent to provide acidity or alkalinity (e.g., preferably a GRAS compoundas described above).

Additional preferred aspects of the present invention provide anadherent liquid (low to high viscosity), gel, or foam formulation,comprising: (i) a food-grade gelling or thickening agent (e.g.,preferably a GRAS compound as described above); (ii) a food-gradeemulsifying or foam stabilization agent (e.g., preferably a GRAScompound as described above); (iii) a food-grade surfactant (e.g.,preferably a GRAS compound as described above); and, (iv) a sanitizingagent (e.g., preferably a GRAS compound as described above).

Further aspects comprise application of heat or a heat source to elevatethe temperature of the inventive adherent antimicrobial barrierformulations to >75° C. Such preferred heated embodiments comprise useof a highly viscous inventive formulation to obtain compositions (e.g.,syrups) with significant heat retentive properties and sufficientadherence to be delivered as a hot solution to a desired surface.

The following non-limiting exemplary ingredients and formulations(TABLE 1) are provided to illustrate preferred aspects of the inventiveantimicrobial barrier formulations:

TABLE 1 Type of Ingredient Ingredient Form of Barrier Gelling/ PectinLiquid, Gel, Foam Thickening Methylated Pectin Liquid, Gel, Foam AgentsGelatin Liquid, Gel, Foam Hydrosylated Gelatin Liquid, Gel, Foam AgarLiquid, Gel, Foam Cornstarch Liquid, Gel, Foam Cross-linked StarchLiquid, Gel, Foam Depolymerized Starch Liquid, Gel, FoamVegetable/Animal Protein Liquid, Gel, Foam Sodium Alginate Liquid, Gel,Foam Carrageenan Liquid, Gel, Foam Sanitizing Organic Acids (acetic,citric, lactic) Liquid, Gel, Foam Agent Acidified Calcium SulfateLiquid, Gel, Foam Acidified Sodium Chlorite Liquid, Gel, Foam Peraceticacid and mixtures thereof Liquid, Gel, Foam Percarbonates Liquid, Gel,Foam Ammonium Hydroxide Liquid, Gel, Foam Quaternary Ammonium SaltsLiquid, Gel, Foam Cetylpyridinium Chloride Liquid, Gel, FoamPolyphosphates Liquid, Gel, Foam Glycolic Acid Liquid, Gel, Foam SodiumMetasilicate Liquid, Gel, Foam Trisodium Phosphate Liquid, Gel, FoamLysozyme Liquid, Gel, Foam Lactoferrin Liquid, Gel, Foam Emulsifier/Calcium Lactate Foam Stabilizer Lecithin Foam Glycerol Foam SurfactantsSodium Lauryl Sulfate Foam Tween 20, 40, 60, 80 Foam

The following non-limiting examples (TABLE 2) further illustratepreferred inventive formulations:

TABLE 2 Ingredients Wt (%) Gel Formulation #1 (pH 1.96) Pectin 25 CitricAcid 2-5 Water 70-73 Gel Formulation #2 (pH 1.6) Pectin 16-33 LacticAcid 5 Water 62-79 Liquid (Syrup) Formulation #1 (pH 1.9) Pectin 2.5Lactic Acid 5 Water 92.5 Liquid (Syrup) Formulation #2 (pH 2) Pectin1.5-3.0 Gelatin 0.5-1.5 Lactic Acid 5 Water 90.5-93.0 Foam Formulation#1 (pH 2) Pectin 0.75 Gelatin 2.5 Lactic Acid 5 Water 91.5 FoamFormulation #2 (pH 1.94) Pectin 0.75 Gelatin 2.5 Lactic Acid 5 Tween 801 Water 90.5

Preferred solid (e.g., gel) forms of the inventive antimicrobial barrierformulations comprise at least one agent selected from the groupconsisting of: from about 5 to about 25% (wt) of one or moregelling/thickening agents (preferably about 5 to about 15% (wt)); asufficient amount of one or more acidic agents to produce a formulationpH lower than about 6 (preferably lower than about pH 3, and generallyachieved with about 0.1 to about 15% (wt) acid agent, or preferablyabout 1 to about 5% (wt) acid agent); a sufficient amount of one or morealkaline agents to produce a pH higher than about 9 (preferably higherthan about 10 and generally achieved with about 0.1 to about 15% (wt)basic agent); about 0.1 to about 15% (wt) of one or more sanitizingagents; and about 0.1 to about 15% (wt) (preferably about 1 to about 5%(wt)) of one or more C₁₋₁₀ alcohols. Preferably, the balance is water,or substantially water.

Preferred liquid (syrup) forms of the inventive antimicrobial barrierformulations comprise at least one agent selected from the groupconsisting of: about 0.5 to about 6% (wt) of one or moregelling/thickening agents (preferably about 1 to about 3.5% (wt)); asufficient amount of one or more acidic agents to produce a pH lowerthan about 6 (preferably lower than about pH 3 and generally achievedwith about 0.1 to about 15% (wt) acidic agent); sufficient amount of oneor more alkaline agents to produce a pH higher than about 9 (preferablyhigher than about 10 and generally achieved with 0 to 15% (wt) basicagent); about 0.1 to about 1% (wt) of one or more sanitizing agents; andabout 0.1 to 15% (wt) (preferably 1 to 5 wt-%) of one or more C₁₋₁₀alcohols. Preferably, the balance is water, or substantially water.

Preferred aerosolized (foam) forms of the inventive antimicrobialbarrier formulations comprise at least one agent selected from the groupconsisting of: about 0.5 to about 6% (wt) of one or moregelling/thickening agents (preferably about 1 to about 3.5 wt-%); asufficient amount of one or more acid agents to produce a pH lower thanabout 6 (preferably lower than about pH 3 and generally achieved withabout 0.1 to about 15% (wt) acidic agent); sufficient amount of one ormore alkaline agents to produce a pH higher than about 9 (preferablyhigher than about 10 and generally achieved with about 0.1 to about 15%(wt) basic agent); about 0.1 to about 15% (wt) of one or more sanitizingagents; about 0.1 to about 10% (wt) (preferably about 1 to about 5 wt-%)of one or more surfactants; about 0.1 to about 10% (wt) (preferablyabout 1 to about 5% (wt)) of one or more emulsifies; and about 0.1 toabout 15% (wt) (preferably about 1 to about 5% (wt)) of one or moreC₁₋₁₀ alcohols; and, the balance water. Preferably, the balance iswater, or substantially water.

In particularly preferred embodiments the inventive antimicrobialbarrier formulations comprise at least one agent selected from the groupconsisting of: from about 0.1 to about 4% (wt) (preferably about 2.5%(wt)) of one or more gelling agents (e.g., Gelatin); from about 0.1 toabout 1% (wt) (preferably about 0.2% (wt)) of one or more foamstabilizing agents; from about 0.05 to about 0.5% (wt) of one or moresurfactants; from about 1 to about 5% (wt) of one or more acid, base orother sanitizing agents; and from about 2 to about 25% (wt) of one ormore alcohols. Preferably, the balance is water, or substantially water.

Example 1

This Example (TABLE 3) demonstrates the viscous nature of two solutionsprepared with different concentrations of pectin (15 and 25%). Thefluidity of viscous solutions formulated with 15 and 25% pectin andheated to 80° C. or left unheated (22° C.) was tested. Specifically, theheated or unheated solutions were drawn up into a 25 ml pipette and leftto drain free of the solution. The time (in seconds) was measured todetermine residence time of the various fluids in the pipette.

TABLE 3 Adherent properties of formulated liquid solutions containingvarious concentrations of pectin as the primary gelling/thickening agentTemperature Volume Time to % Pectin (° C.) (ml) pH Drain (s) 0 (Watercontrol) 22 25 7.2 2.4 15 22 25 2.3 14.5 15 80 25 2.4 3.9 25 22 25 2.1190.5 25 80 25 2.1 19.9

As shown by the data, the relative retention times were enhanced byrelatively low pH and relatively low temperature.

Example 2

This Example (TABLE 4) demonstrates the antimicrobial propertiesconferred by an exemplary liquid formulation composed of 5% lactic acid,2.5% pectin, and 92.5% water. The disinfecting quality of the solutionwas tested on an aqueous culture of Escherichia coli biotype I. For thetest the following ratios of a 10⁵ CFU/ml culture were prepared with theantimicrobial formulation: 9:1; 2:1; and, 1:1. The mixtures were leftfor 30 seconds after which time, serial dilutions were made and platedonto Escherichia coli/Coliform Petrifilms (3M; St. Paul, Minn.). Plateswere incubated at 35° C. for 24 hours and counted to enumeratesurvivors.

Results.

TABLE 4 indicates that at a ratio of 9:1 (Culture:Antimicrobial Barrierformulation), populations were not substantially reduced, while at aratio of 2:1, populations were reduced by >4 log CFU/ml.

Although, the present Example does not provide a sanitizer as defined bythe Environmental Protection Agency (i.e., 5 log reduction of bacterialsuspension using 1 ml of culture with 9 ml of sanitizer), it doesprovide an exemplary sanitizing agent, indicated by the substantialreduction at lower dilution ratios, confirming the antimicrobialproperty of an exemplary low pH adherent formulation.

TABLE 4 Survival (log CFU/ml) of Escherichia coli exposed toantimicrobial formulation consisting of 2.5% pectin, 5% lactic acid, and92.5% water in a liquid phase. E. coli Culture:Antimicrobial Time ofExposure (s) Barrier Formulation (v/v) 0 30 9:1 5.2 4.8 2:1 5.2 <1 1:15.2 <1

Example 3

The Example (TABLE 5) demonstrates, according to preferred aspects ofthe present invention, the efficacy of the inventive barrierformulations in reducing or precluding bacterial contaminationtransferred by the surface of a stainless steel knife, which representsan implement typically used in a food processing operation.Specifically, the adherent antimicrobial barrier property of theinventive formulations was tested to determine the efficacy of saidsolutions to exclude bacterial contamination from food surfaces that maybecome contaminated during the use of implements (such as knives) infood processing. This Example models the operation of a knife in a‘dehiding’ process of cattle in a beef operation.

In such operations, there is a high probability that the exterior ofbeef cattle will be covered with microbiologically-contaminated fecalmaterial, presenting a risk of internalizing the contamination—tootherwise sterile underlying tissue during process cuts. The inventiveviscous barrier solutions (e.g., gel, syrup or foam) have substantialutility in such processes by covering the knife blade and/or theexterior surface of the animal, thereby reducing or precludinginadvertent translocation of bacterial contamination by knifepenetration to otherwise sterile underlying tissue.

Accordingly, to test the ability of the formulated solutions to act as abarrier to minimize bacterial transfer to meat tissue, various relevantscenarios were comparatively evaluated. The scenarios included: touchinga knife surface to meat covered with a fecal inoculum and determiningthe amount of contamination transferred to the knife; touching a knifeto a layer of inventive barrier foam formulation overlaying fecalinoculum on meat and determining the amount of contamination transferredto the knife; and touching a knife to a layer of inventive barrier syrupformulation overlaying fecal inoculum on meat and determining the amountof contamination transferred to the knife.

Additional scenarios, representing common and current industry practiceswere also comparatively evaluated: dipping a blade in 80° C. water,prior to touching a contaminated surfaces as described above; coveringimplements prior to contacting the contaminated surface; and coveringthe meat substrate (here representing the exterior surface of theanimal).

Results.

Table 5 shows that dipping knives into water (80° C.) before contactingthe contaminated meat surface is not effective at preventing or reducingthe transfer of surface contamination to the knife. By contrast, the useof inventive syrup or foam barrier formulations on the knife and/or onthe substrate surface was substantially effective in preventingbacterial contamination of the blade surface from the contaminated meatsurface.

Therefore, according to the present invention, modifications to thetreatment of implements (e.g., knives typically used in the meatslaughtering industry) and/or substrate surfaces to include an adherentbarrier substantially decreases the risk of transferring bacterialcontamination to the knife and, thus, to subsequently contacted surfacesand/or underlying tissues.

TABLE 5 Levels (mean log CFU/ml ± standard deviations) of bacterialcontamination (determined on Aerobic Plate Count Petrifilm; 3M) on aknife surface contacted to meat inoculated with a fecal slurrycontaining 1 × 10⁴ CFU/cm² Escherichia coli. Sample DescriptionBacterial Populations Knife touched to feces 3.8 (0.2) Knife touched tofoam covering feces 0.4 (0.8) Knife touched to syrup covering feces 0(0) Knife dipped in water and touched to feces 3.3 (0.3) Knife dipped inwater and touched to foam 0.1 (0.2) covering feces Knife dipped in waterand touched to syrup 0.2 (0.5) covering feces Knife dipped in waterfollowed by syrup and 1.5 (1.3) touched to feces Knife dipped in waterfollowed by syrup and 0 (0) touched to foam covering feces Knife dippedin water followed by syrup and 0 (0) touched to syrup covering feces

Example 4

The following Example illustrates, according to the present invention,the principles involved in reducing or precluding carcass cuttingimplement-mediated (e.g., cutting knife-mediated) translocation ofhide-born microbial contamination to interior carcass surfaces.

Specifically, FIG. 1 demonstrates the sacrificial protective barrieraspect of the inventive adherent antimicrobial formulations with respectto the use of an implement (i.e., a knife) of a type typically used in ameat processing facility for cutting through a portion of meat.

A knife was dipped in water per standard industry practice, or forcomparison was dipped in an inventive liquid (syrup) formulationcomprising 2.5% (wt) pectin and 5% (wt) lactic acid. The syrup wasdetectably laced with Ethidium Bromide (EtBr) and kept at 23° C. Thedipped knife, in each case, was used to cut through a piece of meathaving dimension of about 4×4×15 cm. After, the incision from the top ofthe meat through to the bottom, a photographic image of the meat wasgenerated in a UV chamber to visualize the EtBr-containing syrup. Themeat was then spread out around the cut to visualize the spread of theEtBr-containing syrup through the piece of meat to observe the abilityof syrup to transfer with the blade through material based on itsadherent properties.

The results show that the inventive adherent syrup formulation wasdelivered to, and sacrificially deposited onto contact surfaces therebyisolating potential surface contaminants from the passing blade duringcutting. Significantly, as evident from the ethidium staining pattern,an adherent, residual non-sacrificed portion of the formulationtransferred with the knife, providing a continuing protective layer tothe knife for at least 3 cm through the 4 cm of meat.

According to preferred aspects of the present invention, the disclosedformulations have novel and substantial utility to reduce or precludecutting implement-mediated transfer of surface contamination duringcutting operations in the food and pharmaceutical industry, and forreducing or preventing transfer of contamination from a contaminatedsurface.

1. A method of reducing or preventing transfer of contamination from acontaminated surface; comprising coating a contaminated surface or aportion thereof with an adherent antimicrobial barrier composition,comprising: from about 0.1 to about 25% (wt) of a gelling or thickeningagent; from about 0.1 to about 10% (wt) of an emulsifier or stabilizer;from about 0.05 to about 10% (wt) of a surfactant; and an antimicrobialagent, whereby transfer of contamination from the surface is reduced orprecluded.
 2. The method of claim 1, wherein the adherent antimicrobialbarrier composition further comprises from about 0.1 to about 15% (wt),or about 1 to about 5% (wt), of one or more C₁₋₁₀ alcohols.
 3. Themethod of claim 1, wherein the gelling or thickening agent is present inan amount selected from the group consisting of from about 0.1 to about4% (wt), from about 5 to about 15% (wt), and about 2.5% (wt), and isselected from the group consisting of pectin, methylated pectin,gelatin, hydrosylated gelatin, agar, cornstarch, cross-linked starch,depolymerized starch, gelling vegetable protein product, sodiumalginate, carrageenan, and combinations thereof.
 4. The method of claim1, wherein the emulsifier or stabilizer is present in an amount selectedfrom the group consisting of from about 0.1 to about 1% (wt), from about1 to about 5% (wt), and about 0.2% (wt), and is selected from the groupconsisting of calcium lactate, lecithin, glycerol, and combinationsthereof.
 5. The method of claim 1, wherein the surfactant is present inan amount selected from the group consisting of from about 0.05 to about0.5% (wt), from about 1 to about 5% (wt), and about 0.2% (wt), and isselected from the group consisting of sodium lauryl sulfate, Tween 20,40, 60, and 80, and combinations thereof.
 6. The method of claim 1,wherein the antimicrobial agent is at least one of an acidic agent and abasic agent, present in an amount selected from the group consisting offrom about 0.1 to about 15% (wt), from about 1 to about 5% (wt), andabout 2% (wt), suitable to impart a pH of less than about 3, or greaterthan about 10, and is selected from the group consisting of acetic acid,citric acid, and lactic acid, acidified calcium sulfate, acidifiedsodium chlorite, peracetic acids, percarbonates, ammonium hydroxide,quaternary ammonium salts, cetylpyridinium chloride, polyphosphates,glycolic acid, sodium metasilicate, trisodium phosphate, andcombinations thereof.
 7. The method of claim 1, wherein theantimicrobial agent is selected from the group consisting of proteases,lipases and phospholipases, alcohols, and combinations thereof.
 8. Themethod of claim 1, wherein the antimicrobial agent is heat.
 9. Themethod of claim 1, further comprising, prior to coating, heating theadherent antimicrobial barrier composition to a temperature equal to orgreater than 80° C.
 10. The method of claim 1, wherein the antimicrobialbarrier composition is provided as a formulation selected from the groupconsisting of semi-solids, gels, liquids, syrups, aerosolizedformulations, foams, colloidal suspensions, and combinations thereof.11. A method of reducing or precluding transfer of surface contaminationduring cutting operations, comprising: coating, prior to cutting througha target surface, at least one of: a cutting implement or a portionthereof; and the target surface or a portion thereof with an adherentsacrificial composition layer, wherein the sacrificial layer ispartially transferable between the cutting implement and the targetsurface during cutting, whereby a protective layer is provided to thecutting implement surface while cutting through the target surface. 12.The method of claim 11, wherein the adherent sacrificial compositioncomprises at least one agent selected from the group consisting of: fromabout 0.1 to about 25% (wt) of a gelling or thickening agent; from about0.1 to about 10% (wt) of an emulsifier or stabilizer; from about 0.05 toabout 10% (wt) of a surfactant; and an antimicrobial agent.
 13. Themethod of claim 12, wherein the adherent sacrificial composition furthercomprises from about 0.1 to about 15% (wt), or about 1 to about 5% (wt),of one or more C₁₋₁₀ alcohols.
 14. The method of claim 12, wherein thegelling or thickening agent is present in an amount selected from thegroup consisting of from about 0.1 to about 4% (wt), from about 5 toabout 15% (wt), and about 2.5% (wt), and is selected from the groupconsisting of pectin, methylated pectin, gelatin, hydrosylated gelatin,agar, cornstarch, cross-linked starch, depolymerized starch, gellingvegetable protein product, sodium alginate, carrageenan, andcombinations thereof.
 15. The method of claim 12, wherein the emulsifieror stabilizer is present in an amount selected from the group consistingof from about 0.1 to about 1% (wt), from about 1 to about 5% (wt), andabout 0.2% (wt), and is selected from the group consisting of calciumlactate, lecithin, glycerol, and combinations thereof.
 16. The method ofclaim 12, wherein the surfactant is present in an amount selected fromthe group consisting of from about 0.05 to about 0.5% (wt), from about 1to about 5% (wt), and about 0.2% (wt), and is selected from the groupconsisting of sodium lauryl sulfate, Tween 20, 40, 60, and 80, andcombinations thereof.
 17. The method of claim 12, wherein theantimicrobial agent is at least one of an acidic agent and a basicagent, present in an amount selected from the group consisting of fromabout 0.1 to about 15% (wt), from about 1 to about 5% (wt), and about 2%(wt), suitable to impart a pH of less than about 3, or greater thanabout 10, and is selected from the group consisting of acetic acid,citric acid, and lactic acid, acidified calcium sulfate, acidifiedsodium chlorite, peracetic acids, percarbonates, ammonium hydroxide,quaternary ammonium salts, cetylpyridinium chloride, polyphosphates,glycolic acid, sodium metasilicate, trisodium phosphate, andcombinations thereof.
 18. The method of claim 12, wherein theantimicrobial agent is selected from the group consisting of proteases,lipases and phospholipases, alcohols, and combinations thereof.
 19. Themethod of claim 12, wherein the antimicrobial agent is heat.
 20. Themethod of claim 11, further comprising, prior to coating, heating theadherent sacrificial composition to a temperature equal to or greaterthan 80° C.
 21. The method of claim 11, wherein the adherent sacrificialcomposition is provided as a formulation selected from the groupconsisting of semi-solids, gels, liquids, syrups, aerosolizedformulations, foams, colloidal suspensions, and combinations thereof.22. An antimicrobial barrier composition, comprising: from about 0.1 toabout 25% (wt) of a gelling or thickening agent; from about 0.1 to about10% (wt) of an emulsifier or stabilizer; from about 0.05 to about 10%(wt) of a surfactant; and an antimicrobial agent.
 23. The antimicrobialbarrier composition of claim 22, further comprising from about 0.1 toabout 15% (wt), or about 1 to about 5% (wt), of one or more C₁₋₁₀alcohols.
 24. The antimicrobial barrier composition of claim 22, whereinthe gelling or thickening agent is present in an amount selected fromthe group consisting of from about 0.1 to about 4% (wt), from about 5 toabout 15% (wt), and about 2.5% (wt), and is selected from the groupconsisting of pectin, methylated pectin, gelatin, hydrosylated gelatin,agar, cornstarch, cross-linked starch, depolymerized starch, gellingvegetable protein product, sodium alginate, carrageenan, andcombinations thereof.
 25. The antimicrobial barrier composition of claim22, wherein the emulsifier or stabilizer is present in an amountselected from the group consisting of from about 0.1 to about 1% (wt),from about 1 to about 5% (wt), and about 0.2% (wt), and is selected fromthe group consisting of calcium lactate, lecithin, glycerol, andcombinations thereof.
 26. The antimicrobial barrier composition of claim22, wherein the surfactant is present in an amount selected from thegroup consisting of from about 0.05 to about 0.5% (wt), from about 1 toabout 5% (wt), and about 0.2% (wt), and is selected from the groupconsisting of sodium lauryl sulfate, Tween 20, 40, 60, and 80, andcombinations thereof.
 27. The antimicrobial barrier composition of claim22, wherein the antimicrobial agent is at least one of an acidic agentand a basic agent, present in an amount selected from the groupconsisting of from about 0.1 to about 15% (wt), from about 1 to about 5%(wt), and about 2% (wt), suitable to impart a pH of less than about 3,or greater than about 10, and is selected from the group consisting ofacetic acid, citric acid, and lactic acid, acidified calcium sulfate,acidified sodium chlorite, peracetic acids, percarbonates, ammoniumhydroxide, quaternary ammonium salts, cetylpyridinium chloride,polyphosphates, glycolic acid, sodium metasilicate, trisodium phosphate,and combinations thereof.
 28. The antimicrobial barrier composition ofclaim 22, where the antimicrobial agent is selected from the groupconsisting of proteases, lipases and phospholipases, alcohols, andcombinations thereof.
 29. The antimicrobial barrier composition of claim22, wherein the antimicrobial agent is heat.
 30. The antimicrobialbarrier composition of claim 22, provided as a formulation selected fromthe group consisting of semi-solids, gels, liquids, syrups, aerosolizedformulations, foams, colloidal suspensions, and combinations thereof.